Human mutL homolog 1 expression characteristic and prognostic effect on patients with sporadic colorectal cancer

The aim of the present study was to analyze the relationship between aberrant human mutL homolog 1 (hMLH1) expression and clinicopathological parameters of patients with sporadic colorectal cancer, and to explore the prognostic effect of aberrant hMLH1 expression in these patients. The relationship was measured by chi-square test and Fisher's exact test. Survival analysis was performed with Kaplan-Meier analysis and Cox regression model to measure 5-year disease-free survival (DFS) and 5-year overall survival (OS) rates. Totally 17.13% of the patients with sporadic colorectal cancer showed aberrant nuclear staining for hMLH1 expression. Aberrant hMLH1 expression was related with tumor pathologic types, tumor location and TNM staging (P<0.05) in the patients with sporadic colorectal cancer. Cox regression analysis indicated important prognostic factors were age (RR: 1.021, 95% CI: 1.003-1.039, P=0.023), mucinous adenocarcinoma (RR: 2.603, 95% CI: 1.705-3.974, P<0.0001), TNM staging (RR: 2.071, 95% CI: 1.170-3.666, P=0.012), lymphangion invasion (RR: 2.013, 95% CI: 1.227-3.303, P=0.006) and aberrant hMLH1 expression (RR: 0.414, 95% CI: 0.216-0.791, P=0.008). Consequently, hMLH1 expression level is related with some clinicopathologic features. Aberrant hMLH1 expression plays a significant part in prognosis for patients with sporadic colorectal cancer and it will promisingly become an independent prognostic factor.